Molecular recognition is at the heart of biology and many biotechnological applications. If cheap and robust synthetic receptors can be prepared for arbitrarily selected drugs, carbohydrate, or oligopeptides, numerous new technologies and biomedical tools will become possible. Improved drug analysis, extraction of drugs or biomolecules from their natural milieu, novel sensors, intervention of biomolecular recognition, and replacing expensive antibodies in affinity chromatography are but some of the possibilities enabled by such antibody-mimicking materials. Molecular imprinting is a powerful way of making synthetic receptors. Although molecularly imprinted polymers, sometimes referred to as plastic antibodies, have found applications in chemical and biological sensing, enzyme-like catalysis, and separation, there are significant challenges facing this technology, including heterogeneous binding sites, low percentage of high-affinity binding sites, incomplete template removal, and difficulty in imprinting in water. The overall objective of this proposal is to fill he gap in the knowledge by developing protein-mimicking molecularly imprinted receptors for a broad range of biologically interesting molecules. The proposed molecularly imprinted nanoparticles (MINPs) can be prepared and purified in 2-3 days without any special techniques, as long as the cross- linkable surfactants and other cross-linkers are available. The MINP receptors, typically 3-5 nm in diameter, resemble proteins in size, hydrophilic exterior, and tailored hydrophobic binding pockets in the core, but easily tolerate long-term storage, high temperatures, and organic solvents due to their heavy cross-linking. The proposed research will lead to robust synthetic receptors for a wide range of biologically interesting guests including hydrophobic drugs, carbohydrates, and oligopeptides. Fundamental structure-activity relationship for these biomimetic receptors will be established through the investigation. The research is expected to open up numerous opportunities for chemists, biologists, engineers, and clinicians in the future as cheap synthetic antibodies become readily available.